This invention relates to live crab butchering apparatus and more particularly to such machines intended to produce two clean sections of shoulders with legs attached.
Despite numerous attempts to automate the process, the large crab species of the North Pacific and other areas are still predominately butchered by hand. This high-paced, repetitive motion task results in large medical and insurance costs for both shore-based and floating processing plants. As the competition for this resource has increased the need for a fast, simple, and reliable machine to perform this job has grown more acute.
Flohr Metal Fabrication of Seattle, Wash., is currently marketing an automatic crab butchering machine that attempts to fill this need.(U.S. Pat. No. 5,401,207) This machine is receiving poor reception in the industry due to its high complexity and cost. Furthermore, this machine is capable of butchering the Bairdi and Opillio species but not the King Crab species which are substantially larger.
U.S. Pat. No. 4,293,981 to Charles M. Smith discloses a crab butchering machine specifically intended for the above species. This machine also suffered poor reception due to complexity and lack of ready accomodation for the wide range of crab sizes.
U.S. Pat. No. 4,073,041 Davis et al, shows a crab butchering machine wherein the crab are input into the machine with their carapace down, as in the present invention. The similarity ends here, however, as this machine is designed for small crab species known as "Rock", "Jona" and "Blue" crab.
There are numerous other patents disclosing machines intended to process small crab species. This prior art is of limited applicability in that none of these machines have been modified to successfully process the larger species even though there has been substantial economic impetus to do so.
The present invention is a significant advance over the above prior art in several ways. First, all of the above machines utilize a crab conveying method that entails an indexing system that the operator must match to some part of the crab during the infeed process. This requires both concentration and time. Accordingly, such machines are fatiguing to operate and have low potential maximum production rates. In the present invention, crab can be fed at any time, as fast as the operator can feed them. Secondly, the machine of this invention adjusts rapidly to accomodate large variations in crab size. Third, the removal of the carapace and tail, and the splitting of the crab body are performed in one operation. Next, this invention utilizes a unique combination of gilling and cleaning implements to ensure high quality crab sections that are ready to pack.
Additionally, the machine of the present invention is inherently safe. Most of the prior art employs a sharp rotary saw blade to split the crab body. This invention utilizes a blunt-edge blade that won't cut skin. Also the blade is torque limited as are the high-friction belts that convey the crab. A few extra pounds of resistance will produce an instant power stoppage.